Association Between Depression Symptoms and Disability Outcomes in Older Adults at Risk of Mobility Decline

Objective: To assess the association between depression symptoms and physical functioning and participation in daily life over 2 years in older adults at risk of mobility decline. Design: A secondary analysis of 2-year observational data from the Boston Rehabilitative Impairment Study of the Elderly. Setting: Nine primary care clinics within a single health care system. Participants: Participants (N=432; mean age +/- SD, 76.6 +/- 7.0y; range, 65-96y; 67.7% women) were community-dwelling adults (>65y) at risk of mobility decline. Interventions: Not applicable. Main Outcome Measures: Secondary data analyses of the Late Life Function and Disability Instrument (primary outcome), Short Physical Performance Battery (secondary outcome), and Patient Health Questionnaire-9 (PHQ-9) (predictor). Measures were administered at baseline, 12 months, and 24 months. Participants completed a self-report survey asking about 16 medical comorbidities, and demographic information was collected at baseline. Results: Participants had an average +/- SD PHQ-9 score of 1.3 +/- 3.1, ranging from 0 to 24 at baseline. Twenty-nine percent of participants reported a history of depression. Greater depression symptoms were associated with lower physical functioning (unstandardized beta [B]=-0.14, SE=0.05, P=.011) and restricted participation (frequency subscale: B=-0.21, SE=0.11, P=.001; limitation subscale: B=-0.45, SE=0.04, P<.001) cross-sectionally over 2 years. PHQ-9 was not significantly associated with the rate of change in Late Life Function and Disability Instrument score over 2 years. Conclusions: Treating depression in primary care may be an important strategy for reducing the burden of functional limitations and participation restrictions at any 1 time. Further research is needed on treatment models to cotarget depression and physical functioning among at-risk older adults.